Hey Gwern --
Do you do github? If so, send me a merge request:
https://github.com/haskell-pkg-janitors/X11/commits/master
If not, I'll happily apply this patch by hand. Looks pretty easy.
I intend to do a release of 1.5.0.1 in the next few days (with updated
maintainer information, some GHC 7.3 compatibility patches, and the
patch for big-endian compat), but would happily make it a 1.5.1.0 to
include this. =)
~d